> the electronic vac. advance. Okay 78 F-250, 400M, Carter 4v,
> Edelbrok performer. Under normal driving it runs fine, but when It
> is under a load like going up a hill or towing it pings, it seems
> like it does it when I am giving the engine alot of gas but the RPMs
> are low, because if the trans mission kicks down and the RPM comes
> up it will stop. The vacume is comming off the ported valve on the

I don't know how to make it work off the ported tap but the problem
you need to solve is that it's not backing out far enough at WOT to
account for the faster burning of the charge so it pings.

I backed my initial out to 8 degrees and also backed the spring
pressure off on the vac to allow more advance to be pulled in at a
lower vacuum (higher manifold pressure, less in of hg) and kept my
cruise, light throttle and throttel response but got rid of the ping.

What I have discerned from my fooling around is that the engine needs
lots of advance at cruise (45 - 50 deg's) with light throttle
(equilibrium) and also at idle so without the vac you can't get it
and economy will suffer but at near WOT you need less advance,
roughly whatever the mechanical is at so the vac needs to fully
retard. I don't know if it does that with the ported and don't have
one on my carb so I can't test it either but that's exactly what it
does with manifold vac and it works quite will on my 351M bronco with
33's and 3.5 gears.

To test, disconnect the vacuum advance and try the same hill it might be
sluggish but it probably won't ping. Check your vacuum advance can and
compeer it to the one listed below. The combo below is working great for
me. (87 octane fuel in my 460) also I am running the vacuum can at its
weakest spring pressure.

You can find out what your timing is doing with a timing light, tach and
a few steps:

1)Disconnect vacuum advance.
2)With timing light read the initial advance.
3)slowly speed up the engine and watch the advance change.
4)Note the RPM when the advance starts to move.
5)Check it every 500 or so RPM.
6)And finally note the maximum it advances.

You have just established your mechanical advance curve!

7)with the engine at idle attach a vacuum pump with gauge ( a few
pieces of vacuum hose, vacuum gauge, a "T" vacuum line fitting and your
own lungs will do the same)
8) With timing light in hand increase the vacuum to the canister (RPM
will increase so be sure you stay under the RPM at which the mechanical
starts to come in. If mechanical comes in at a really low in RPM then
you can reduce theidle speed every time you increase the vacuum an
increment to keep themechanical out of the picture.)
9)Note the amount of vacuum when the advance starts.
10)Check it in increments of 5 inches of mercury.
11)And finally note the maximum it advances

You have just established your vacuum advance curve!

Now you can start playing with various springs, vacuum cans, ETC.

I went to the wrecking yard and found two different single port advance
units( not the double port type with one port blocked. Also keep in mind
I am in California, and the junk yard cars are mostly from around here
and some of the parts may be California only )The one that worked still
had the OEM dist tag on the dist ( helps in the future. )It has the
following markings:

C41 under the can, 12 on the arm that attaches to the pickup plate in
the dist, an internal stop that limits vacuum advance to about 20 deg's
and it has a relatively soft spring ( as compared to the other type I
found)

The dist. tag reads as follows:
82
D7AE
2127
UA
8L 17

Other then the D7A = 1977, full-size, I have no idea what the tag means.

The other vac canister has the following markings:

C37 under the can, 10 on the arm that attaches to the pickup plate in
the dist, no internal stop so the vacuum advances to about 30-40 deg's
and it has a relatively stiff spring ( as compared to the C41 type )

Is it me am I retarded...I've looked on both fram rails for my Vin
on my 68 F-100..Could it be under the power steering box???It is on
the top of the frame..right??Is it stamped any where else???Anybody
with a 67-72 that found theres please respond.
Joe

my MSD destributer gives 28 deg max mech. timing advance. (part#8580)
it comes with 3 other stops that limit it down to a minumum of 18 deg.
it also comes with springs that can be changed to bring in full advance from 2500 to 5500 rpm.
i have the advance on mine locked out to use the timing computer.
this mech. advance of 28 + inital of say 10 gives total of 38 without any vacuum.

> THIS IS NOT A FLAME!
> It is just my two cents worth.
>
> The mechanical advance responds to engine SPEED only.
>
> Vacuum advance responds to engine LOAD only.

They also allow more mechanical range
to obtain the ideal "compromise" for best high rpm power without
grenading the engine which everyone seems to agree is about 38 max
total and about 10 - 12 initial but a stock Ford distributor can't
give you that much so many go with MSD etc. which probably does,
don't know, haven't checked into it. Maybe someone out there knows
for sure, maybe in the spec sheet for your MSD or Mallory etc.? I'd
be interested it that info :-)

gary,
where was the truck pull? my girlfreind pulled with my dodge v10 on aug. 31 at Newfoundland PA.
she placed first against the other trucks. distance - 235.
could this be the pull you mentioned?
i know my dodge pulls very well against even built trucks -my dodge is stock :).
and then it can tow my ford to the track and home again with the air on and the stereo kickin' in complete comfort.

> i'll steer away from the theoretical for now, and just tell you
> about one of my engines. i ran a '68 460 with stock manifolds,
> 11.5:1 compression, stock heads, 600 holley, and a good street cam
> for 2 years. the timing was a ford destr. with the vacuum unhooked
> and as far as i know stock springs-weights. i ran any gas, with
> very few ping or detination problems.

My 460 seems to be very tolerant of timing and fuel too so I
attribute this more to the wedge head design but whatdoiknow :-)

> sometimes things just plain work right, even if they seem like they
> shouldn't. sure, more mileage would be possible, but 10 ain't bad.
> i could go 4 wheeling all day on a tank sometimes.

The converter allows the engine to stay near or above it's torque
peak so all in is the right solution probably in this case?? :-)
Probaly should use 90 wt oil for lube instead of pure murcury for
traction :-) Guy at the races last night said he watched a Dodge
truck outpull Fords and Chevies at a truck pull and I suggested the
above may be the case :-)

I knew I just read something on truck bed coating. I found it now who's
going to clean-up this mess! ;] It's in the Sept issue of Sport Truck. Yes
it's a semi-new issue, I should have thought of the bathroom in the first
place.
They speak highly of the way it turned out, but reading the process...
There is major cleaning and it took 10 cans of Dupli-Color to do a Ford
Ranger $6.99 to $7.99 a can suggested retail, I wouldn't call it the cheap
easy way to go, but perhaps the best!
P/E-M for copie

>I had to put a different box on my '79 F-150 last year after being rear
>ended. I will eventually get around to painting it to match the rest of
>the truck, (yes, I know it's ugly). I've been thinking about whether to
>paint the inside of the box with a stock paint finish or use a spray-on
>bedliner. I'm interested in hearing what you favor and why. I would be
>interested in either commercially applied or DIY finishes and the costs
>involved, results, what works, what doesn't , etc.
>I don't care much for plastic bedliners, just my preference.
>
>later,
>dale c.
>+-------------- Ford Truck Enthusiasts - 1979 and Older --------------+
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I'm in the process of putting a '54 F-250 back on the road, and while I
won't be converting to 12 volts immediately, I will be looking into it by
spring or thereabouts. Hence, I am on a fact-finding mission.
I'm considering two alternatives: convert to the '56 and later 12 volt
generator and stay with the original look of the engine compartment, or
converting to a Ford alternator like the spare I have for my '65 Comet. I
already know I'll have to make other changes to account for the reversal in
polarity, i.e. a new starter and heater motor, etc, but I'm a lttle fuzzy
about wiring up the new generator or alternator.
Bear in mind that the truck is destined to be a daily driver, so
reliability is my primary concern. High amp capacity is not a concern,
because I can't afford an expensive stereo. I have noticed that Ford
continued to use a derivative of the alternator they started to use in '65
up until about '93, making it an attractive choice. Any way, can anybody
offer some suggestions on wiring in a new alternator or generator?
I'm probably throwing a monkey wrench into the works concerning the
discussion of vacuum and mechanical advance, but a mechanical advance only
conversion is popular among the air-cooled VW crowd because the mechanical
advance distributor (Bosch 009) actually provides better mileage AND
performance than the stock vacuum advance distributor does. I've had good
luck on American iron by setting my initial advance to the 10-12 degree
range, and this on a '59 (un-named competition to Ford). It consistently
delivered 20 mpg on the highway, and needed the power down low to overcome
the two-speed automatic.

> I don't know how to make it work off the ported tap but the problem
> you need to solve is that it's not backing out far enough at WOT to
> account for the faster burning of the charge so it pings.
>
> I backed my initial out to 8 degrees and also backed the spring
> pressure off on the vac to allow more advance to be pulled in at a
> lower vacuum (higher manifold pressure, less in of hg) and kept my
> cruise, light throttle and throttel response but got rid of the ping.
>
> What I have discerned from my fooling around is that the engine needs
> lots of advance at cruise (45 - 50 deg's) with light throttle
> (equilibrium) and also at idle so without the vac you can't get it
> and economy will suffer but at near WOT you need less advance,
> roughly whatever the mechanical is at so the vac needs to fully
> retard. I don't know if it does that with the ported and don't have
> one on my carb so I can't test it either but that's exactly what it
> does with manifold vac and it works quite will on my 351M bronco with
> 33's and 3.5 gears.

Hi Gary,
I'm trying to understand your description...please let me know if
this is right.
You're saying that with a lighter spring, the vacuum advance will
provide more advance
at a given vacuum hg pressure. Is this correct? I thought pinging
would occur
with too much advance so wouldn't you use a heavier spring to cut down
on the
amount of vacuum advance? I'm confused...HELP!

Don
Allen, Texas

PS. Anyone out there got a recommendation for a good adjustable timing
light?
How much should I expect to spend on it? How about timing tape.....

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